Stability of Ba-Ferrite Magnetic Recording Media.

Stress and temperature stabilities of Ba-ferrite perpendicular magnetic recording media have been investigated. The stress-induced rate of decrease of remanent magnetization in the media was found to be as small (1 × 10^-5 per kg/cm²) as the values for metal and Co-γ-Fe₂O₃ media. The remanent magnetization in the perpendicular direction remains almost constant in the temperature range from -10 to 80°C. When signals are reproduced with an 8-mm VCR in the still-frame mode, the output decreases after 120 min, and the drop in output after 10 million passes with a 3.5-in floppy disk drive was less than 1 dB. These results confirm the excellent stability of Ba-ferrite recording media.